The Weird and The Wonderful

// Returns a string containing the decoded representation of a range of
// bytes in a byte array.
//
// Internally we override this for performance
//
[Pure]
public virtual String GetString(byte[] bytes, int index, int count)
{
    return new String(GetChars(bytes, index, count));
}

The Unicode Standard requires decoders to
"... treat any ill-formed code unit sequence as an error condition. This guarantees that it will neither interpret nor emit an ill-formed code unit sequence."

The standard also recommends replacing each error with the replacement character "�" (U+FFFD).

These recommendations are not often followed.

         --------------------------------------------------------------------
         | My custom Decoder                                                |
         |                                                                  |
bytes ---------> Is UTF-8 encoded multi-byte?---NO----------------------------- chars -->
         |   ^                              |                               |
         |   |                              |    --------------------       |
         |   |                              |    |                  |       |
         |   |                              YES----> UTF-8 decoder ----V    |
         |   |                                   |__________________|  |    |
         |   |                                                         |    |
         |   ^---------------------------------------------------------<    |
         |                                                                  |
         |__________________________________________________________________|

//first notice that I'm appending two items to the formData.
// 1. string uuid
// 2. journalEntry object with numerous values

var formData = new FormData();
formData.append("uuid",currentUuid);

var entryId = 9;
var jentry = {
        Id:entryId,
        Title: titleText,
        Note: noteText,
        Created: createdDate,
        Updated: null
    };

// You have to do this weird thing to add the data to FormData.

 for (var key in jentry) {
        formData.append(key, jentry[key]);
   }

public ActionResult Save([FromForm] String uuid,[FromForm] JournalEntry jentry)

public class JournalEntry{
    public Int64 Id{get;set;}
    public String? Title{get;set;}
    public String Note{get;set;}
    public String Created{get;set;}
    public String? Updated{get;set;}
}

public class JournalEntry{
    public String Id{get;set;}
   // ....snip....